Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

(a) Overall objective: Design a water tank that will hold a volume of water V =

ID: 1712868 • Letter: #

Question

(a) Overall objective: Design a water tank that will hold a volume of water

V = 5.00 x 105 liters = 500 m3at the lowest cost.

(b) Brainstorm, gather information. Hint: keep it simple. Work with the geometries you are familiar with. You do not need to try ‘crazy’ tank geometries. (20x20x20) Record all your ideas.

(c) Construction costs:

$250 /m2 for flat surface,

$300/m2 for cylindrical surface and

$400/m2 for spherical surface.

(d) Formulas:

Volume of cylinder, Vc =r2h,

Volume of sphere, Vh = (4/3)r3,

surface area of cylinder (no base or lid), Sc = 2rh,

surface area of sphere, Sh = 4r2.

Also 1m3 = 1000 L.

Discuss all the different shapes you considered, as well as the process you followed to select the cheapest alternative.

Show all calculations for your selected alternative.

Explanation / Answer

Since the cost is minimum for flat surface construction, we should go for a cylinderical tank with lesser height and greater dia.

On calculating the volume by trial and error method, we find the following dimensions for the tank

Radius - 7m

Height - 3.248m

Volume of the tank = r2h = 3.14*7*7*3.248 = 499.99 ~= 500 m3

Hence, the construction cost will be

1) Flat surface r2               

Cost = $ 250 / m2

2) Cyliderical surface 2rh

Cost = $ 300 / m2

Total Cost = 250*r2 + 300*2rh = $ 81340 approximately